Gary Walker blamed a "culture of fear" at the highest levels in the health service for attempts to silence critics

The former head of an NHS trust being investigated over high mortality rates has spoken out over patient safety concerns - in defiance of a legal gag.

Gary Walker was sacked in 2010 as chief executive of United Lincolnshire Hospitals Trust for gross professional misconduct over alleged swearing at a meeting. He claims he was forced to quit for refusing to meet Whitehall targets for non-emergency patients and was then gagged from speaking out as part of a settlement deal.

Mr Walker said he warned senior civil servants that he was confronted with the same choices that resulted in the Mid Staffordshire NHS Foundation Trust scandal. He blamed a "culture of fear" at the highest levels in the health service for attempts to silence critics.

Last week's damning Francis report into the Mid Staffs scandal recommended a ban on gagging orders imposed on NHS whistleblowers and Mr Walker's case has been raised in the Commons.

"It's a simple decision: you have emergency care or you have care that could wait," Mr Walker told BBC Radio 4's Today. "It's not nice to wait but it could wait and therefore we chose as a board - it was not just me - that ... emergency care should take priority."

He said he was ordered by the East Midlands Strategic Health Authority to meet the 18-week non-emergency target "whatever the demand" and was told to resign when he would not do so. The authority told the BBC it "utterly refuted" Mr Walker's claims and acted at all times "in the interest of patients".

The Department of Health said: "The Government has taken a series of steps to encourage an open dialogue, including changing the NHS Constitution to enshrine the fact that NHS organisations should support staff who raise concerns, ensure those concerns are fully investigated and ensure that there is someone independent, outside of their team, to speak to.

"That change also set out a legal right for staff to raise concerns about safety, malpractice or other wrongdoing without suffering any detriment. We have consistently made clear to the NHS that local policies should prohibit the inclusion of confidentiality gagging clauses in contracts of employment and compromise agreements which seek to prevent the disclosure of information which is in the public interest.

"Sir David Nicholson (head of the NHS Commissioning Board) has also written to NHS organisations reminding them of their responsibilities in relation to compromise agreements. As we made clear in our initial response to the Francis Inquiry last week, the culture in the NHS needs to change and high-quality patient care must be paramount."

The BBC reported that Mr Walker had been threatened with legal action because of the interview.